This invention relates to a holder for the stationary die of a thread rolling machine of the type in which a movable die is reciprocated back and forth past the stationary die to form threads on the shanks of fastener blanks which are fed successively between the dies. A thread rolling machine of this general type is disclosed in Jackson U.S. Pat. No. 3,926,026.
In such a machine, the fastener blanks usually are delivered to the dies along a slotted track which terminates adjacent one end of the stationary die. Each time the movable die is retracted, a pusher engages the leading blank in the track and feeds such blank into the gap between the dies. To enable proper feeding of the blank, it is necessary that the end of the track be precisely positioned relative to the upper edge of the thread forming face of the stationary die.
Most screws blank are made on a cold forming machine. When the dies of the cold forming machine are new, the shanks of the blanks usually are cylindrical. But, as the dies of the cold forming machine wear, the shanks of the blanks may be formed with a noncylindriical shape and may taper from the head of the shank to the tip thereof. Accordingly, different batches of blanks of the same nominal size may have different shapes. To compensate for the different shapes and enable the threads to be properly rolled, it is necessary from time to time to tilt the stationary die of the thread rolling machine relative to the movable die. If, for example, the thread rolling machine is changed over from running a batch of cylindrical blanks to running a batch of tapered blanks, it is necessary to tilt the lower portion of the stationary die toward the movable die in order to accommodate the taper.